you should just put this question in your other topic- keep everything together. People will buy bighorn sheep horns and spend hours upon hours preparing it for the bow. - There are some good examples on this forum. When horn bows are built, glueing on the horn is NOT the last step- I'm sure there is a very good reason for this.
This next part is the part you don't want to hear, so navigate away from this page now....
You have put lots of work into the bow, and it looks pretty good as far as tiller, but you have your steps out of order. It will be a great challenge to "save" this bow, and if you use horn, you'll probably triple your time investment and my guess is that it will not work. I recommend that if you MUST continue on this bow, do whatever is quickest- which is to laminate on a wood belly with gap-filling epoxy- this MIGHT work. Now comes the part you really really don't want to hear- if you just want a good bow you can trust, start over. Get a nice piece of osage and make a plain old selfbow. We will help you.